Let's begin! In a pot place enough water, bring to a boil and add the pasta. Cook the pasta al dente. While the pasta is cooking take a rectangular baking tray 40cm by 30cm and deep enough to fit two layers plus the cream on top. Drizzle it with a little olive oil and set aside. Once the pasta is ready, drain the water and add half of the pasta to the tray to cover the bottom. Keep the rest of the pasta for the next layer. Take another pot and place the olive oil in it. Grate the onion in a food processor or using a grater and add it in the olive oil. Bring to a high heat and cook until the onion is soft. Add the meat and keep stirring. Add the salt and pepper. Keep the heat on high to brown the meat. Once the meat is brown, add the tomato sauce and stir again. Add the water, cover, reduce the heat to medium and simmer for 15 minutes. Once the meat sauce is ready, spread it evenly on top of the pasta. Grate the cheese and sprinkle it all over the meat sauce. Finally, add the other half of the pasta on top of the meat sauce. Now let's make the béchamel cream. First grate the cheese. In a pot add the butter and olive oil and bring to a heat. Once the butter has melted and it is sizzling hot, add the flour and using a whisk stir very fast. Keep whisking for 2 minutes to cook the flour. Reduce the heat to low and slowly add the milk while whisking. Add the salt and bring the heat to high again. Keep whisking so the sauce doesn't get stuck on the bottom of the pot. Slowly you will notice the cream become thicker. Keep whisking for 3 - 4 minutes or until the sauce gets thick. Once it is getting thicker, add the grated cheese and keep whisking. This will make the sauce a little thicker. Once the sauce is thick remove form the stove. Beat the two eggs well. Slowly add them to the sauce while whisking fast so the eggs don't cook. Your sauce is now ready. Pour it on top of the pasta. Sprinkle with some grated cheese on top and place it in a preheated oven at 170 degrees celsius. Cook for 1 hour.When it is ready, let it cool a little before you cut it into squares and serve it. Enjoy!